Wednesday, September 7, 2011

design | Sun Wall at Sun Farm

As home heating oil prices move inexorably upward, the search for clever use of the sun for heat moves to a higher priority. While numerous “out of the box” solutions are to be found (photovoltaic panels, hot water panels, air heating panels), one of the greatest challenges is to integrate the appliance with the architecture. Too often, rectangular aluminum panels are seen perched precariously on their corner, reclined diagonally in an attempt to find the perfect 90 degree relationship to the noon sun.

This house was designed with a large south-facing façade to welcome the sun to two aspects: the long array of windows was placed to allow the sun’s heat to enter and heat the living room as passive heating; in addition, the large timber trellis was envisioned as a mounting system for a photovoltaic array. Unfortunately, the photovoltaics had to be cut due to high cost, leaving the bare open space above the living room windows.

The current project utilizes this perfect setting in the most cost-effective manner by creating an extremely thin “greenhouse” along the southern wall. The outer skin is a transparent fiberglass fastened to a simple wood frame, with cedar trim. The sunlight penetrates the fiberglass, heating the thin air space just as a car is heated by the sun in the parking lot. The heated air, being lighter, moves upward and into the house through a vent. A second vent at the bottom of the wall brings cooler air into the heating chamber from the lower part of the room; in this way, a thermosiphon is created which will perpetually circulate the air, as long as it is heated by the sun.

We are looking forward to the cool days of fall to try it out!